Philips 28PW9528, Service Manual

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Circuit Descriptions, Abbreviation List, and IC Data Sheets
EN 112 EM5.1E 9.
9.
Circuit Descriptions, Abbreviation List, and IC Data Sheets
Index of this chapter
1.
Introduction
2.
Block diagram
3.
Double Window
4.
Abbreviation list
5.
IC Data Sheets
Note:
•
Only new circuits (compared to the EM5E) are described.
For the other circuit descriptions, see the manual of the
EM5E. This manual is available in different languages:
–
3122 785 12560 = English.
–
3122 785 12571 = German.
–
3122 785 12581 = French.
•
Figures can deviate slightly from the actual situation, due
to different set executions.
•
For a good understanding of the following circuit
descriptions, please use the diagrams in chapter 6 and 7.
Where necessary, you will find a separate drawing for
clarification.
9.1
Introduction
For the EM5.1E chassis, there are three ranges foreseen, with
the following delta's (compared to the EM5E):
•
93xx: No NexTView level 3, No 3rd SCART, No PIP, Eco
Scavem, Virtual Dolby Surround.
•
94xx: New RC, 2-tuner PIP/DW, 3rd SCART with PIP/DW
input, Auto Scavem, Virtual Dolby Surround.
•
95xx: New RC, 1-tuner PIP/DW, 3rd SCART with PIP/DW
input, Auto Scavem, Dolby ProLogic.
The chassis consists of a full sized LSP/SSP combination and
a smaller double sided four layer SSB, which is mounted on the
SSP using a SIMM connector. The main functionalities are:
•
LSP: supply, deflection, and sound amplification.
•
SSP: tuner input, SIMM interface, I/O, and interface
provisions for extended functions such as PIP.
•
SSB: core TV functionalities, being TXT/control, video and
audio decoding, feature box, video featuring, and sync/
geometry control.
The LSP (single sided) is built up very conventional, with hardly
any surface mounted components on the copper side. Similar
with the EM3 (but different as with the MG-chassis), the EM5
LSP has a very large 'hot' part, including both deflection coils.
The SSB is a high tech module (four layer, 2 sides reflow
technology, full SMC) with very high component density and
complete shielding for EMC-reasons. Despite this, it is
designed in such a way, that repair on component level is
possible. To achieve this, attention was paid to:
•
The position of service test lands: most of them are at the
Tuner side.
•
Accessibility (Tuner side). If there are still problems with
the accessibility, one can order an extension board (see
parts list).
•
Clearance around surface mounted ICs (for replacing).
•
Detailed diagnostics and fault finding is possible via
ComPair.
In the architecture, provisions are made for more features/
extensions like:
•
Wireless surround sound.
•
Integrated DVD-player.
The availability of Double Window (DW) or Picture In Picture
(PIP) depends on the model range. There are 2 different
executions, depending on the number of tuners:
•
One Tuner: The TV has only one tuner (on the LSP), so the
PIP-picture can be either from this tuner or from an external
AV-source.
•
Two Tuners: In this case there are 2 separate tuners, so
the main picture and the DW picture are independently
selectable. The IF signal from the main tuner is processed
on the SSB, while the IF signal from the 2nd tuner is
processed by a 2nd BOCMA video processor on the DW-
panel. The source selection is done via an I/O expander.